For Filmore, slavery was a moral wrong, and imposing on states’ rights was a legal wrong, but for U.S. history, the chimera of legislation that became the Compromise of 1850 was a catastrophic mistake.

Adams’ mistake was not, as some would have it, in angrily prosecuting his political enemies; it was, rather, in allowing others within his administration to pursue acts which went against his avowed political principles and instincts.